I actually did that trip, from San francisco via Seoul to Singapore. For those that think nobody in their right mind would pay that. Well I didn't, my company did. If I include all the segments and layovers (I live in Montreal), I was in transit for 29 hours. I would not have been able to work at my arrival in Singapore if I had been in coach during this whole time. For a business, paying 25k$ to get a specialist over so they can deliver that project on time, is nothing, they get millions in return.